[Intel-xe] [PATCH v2 03/31] drm/sched: Add DRM_SCHED_POLICY_SINGLE_ENTITY scheduling policy
Matthew Brost
matthew.brost at intel.com
Mon May 22 01:16:21 UTC 2023
On Mon, May 08, 2023 at 02:40:24PM +0200, Thomas Hellström wrote:
> An question below, with that addressed (possibly without change)
>
> although I'm not a scheduler expert and we should ideally have additional
> reviewers,
>
> Reviewed-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
>
> On 5/2/23 02:16, Matthew Brost wrote:
> > DRM_SCHED_POLICY_SINGLE_ENTITY creates a 1 to 1 relationship between
> > scheduler and entity. No priorities or run queue used in this mode.
> > Intended for devices with firmware schedulers.
> >
> > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> > ---
> > drivers/gpu/drm/scheduler/sched_entity.c | 64 +++++++++++++++++++-----
> > drivers/gpu/drm/scheduler/sched_fence.c | 2 +-
> > drivers/gpu/drm/scheduler/sched_main.c | 63 ++++++++++++++++++++---
> > include/drm/gpu_scheduler.h | 8 +++
> > 4 files changed, 115 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
> > index 2300b2fc06ab..8b70900c54cc 100644
> > --- a/drivers/gpu/drm/scheduler/sched_entity.c
> > +++ b/drivers/gpu/drm/scheduler/sched_entity.c
> > @@ -83,6 +83,7 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
> > memset(entity, 0, sizeof(struct drm_sched_entity));
> > INIT_LIST_HEAD(&entity->list);
> > entity->rq = NULL;
> > + entity->single_sched = NULL;
> > entity->guilty = guilty;
> > entity->num_sched_list = num_sched_list;
> > entity->priority = priority;
> > @@ -91,7 +92,15 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
> > RB_CLEAR_NODE(&entity->rb_tree_node);
> > if(num_sched_list) {
> > - entity->rq = &sched_list[0]->sched_rq[entity->priority];
> > + if (sched_list[0]->sched_policy !=
> > + DRM_SCHED_POLICY_SINGLE_ENTITY) {
> > + entity->rq = &sched_list[0]->sched_rq[entity->priority];
> > + } else {
> > + if (num_sched_list != 1 || sched_list[0]->single_entity)
> > + return -EINVAL;
> > + sched_list[0]->single_entity = entity;
> > + entity->single_sched = sched_list[0];
> > + }
> > }
> > init_completion(&entity->entity_idle);
> > @@ -125,7 +134,8 @@ void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
> > struct drm_gpu_scheduler **sched_list,
> > unsigned int num_sched_list)
> > {
> > - WARN_ON(!num_sched_list || !sched_list);
>
> Is there a way to get to the drm device so we can use drm_WARN_ON() here and
> below? I figure not?
>
Correct, no way to resolve the DRM device.
Matt
> Thanks,
>
> Thomas
>
>
> > + WARN_ON(!num_sched_list || !sched_list ||
> > + !!entity->single_sched);
> > entity->sched_list = sched_list;
> > entity->num_sched_list = num_sched_list;
> > @@ -195,13 +205,15 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity)
> > {
> > struct drm_sched_job *job;
> > struct dma_fence *prev;
> > + bool single_entity = !!entity->single_sched;
> > - if (!entity->rq)
> > + if (!entity->rq && !single_entity)
> > return;
> > spin_lock(&entity->rq_lock);
> > entity->stopped = true;
> > - drm_sched_rq_remove_entity(entity->rq, entity);
> > + if (!single_entity)
> > + drm_sched_rq_remove_entity(entity->rq, entity);
> > spin_unlock(&entity->rq_lock);
> > /* Make sure this entity is not used by the scheduler at the moment */
> > @@ -223,6 +235,20 @@ static void drm_sched_entity_kill(struct drm_sched_entity *entity)
> > dma_fence_put(prev);
> > }
> > +/**
> > + * drm_sched_entity_to_scheduler - Schedule entity to GPU scheduler
> > + * @entity: scheduler entity
> > + *
> > + * Returns GPU scheduler for the entity
> > + */
> > +struct drm_gpu_scheduler *
> > +drm_sched_entity_to_scheduler(struct drm_sched_entity *entity)
> > +{
> > + bool single_entity = !!entity->single_sched;
> > +
> > + return single_entity ? entity->single_sched : entity->rq->sched;
> > +}
> > +
> > /**
> > * drm_sched_entity_flush - Flush a context entity
> > *
> > @@ -240,11 +266,12 @@ long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout)
> > struct drm_gpu_scheduler *sched;
> > struct task_struct *last_user;
> > long ret = timeout;
> > + bool single_entity = !!entity->single_sched;
> > - if (!entity->rq)
> > + if (!entity->rq && !single_entity)
> > return 0;
> > - sched = entity->rq->sched;
> > + sched = drm_sched_entity_to_scheduler(entity);
> > /**
> > * The client will not queue more IBs during this fini, consume existing
> > * queued IBs or discard them on SIGKILL
> > @@ -337,7 +364,7 @@ static void drm_sched_entity_wakeup(struct dma_fence *f,
> > container_of(cb, struct drm_sched_entity, cb);
> > drm_sched_entity_clear_dep(f, cb);
> > - drm_sched_wakeup(entity->rq->sched);
> > + drm_sched_wakeup(drm_sched_entity_to_scheduler(entity));
> > }
> > /**
> > @@ -351,6 +378,8 @@ static void drm_sched_entity_wakeup(struct dma_fence *f,
> > void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
> > enum drm_sched_priority priority)
> > {
> > + WARN_ON(!!entity->single_sched);
> > +
> > spin_lock(&entity->rq_lock);
> > entity->priority = priority;
> > spin_unlock(&entity->rq_lock);
> > @@ -363,7 +392,7 @@ EXPORT_SYMBOL(drm_sched_entity_set_priority);
> > */
> > static bool drm_sched_entity_add_dependency_cb(struct drm_sched_entity *entity)
> > {
> > - struct drm_gpu_scheduler *sched = entity->rq->sched;
> > + struct drm_gpu_scheduler *sched = drm_sched_entity_to_scheduler(entity);
> > struct dma_fence *fence = entity->dependency;
> > struct drm_sched_fence *s_fence;
> > @@ -456,7 +485,8 @@ struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity)
> > * Update the entity's location in the min heap according to
> > * the timestamp of the next job, if any.
> > */
> > - if (entity->rq->sched->sched_policy == DRM_SCHED_POLICY_FIFO) {
> > + if (drm_sched_entity_to_scheduler(entity)->sched_policy ==
> > + DRM_SCHED_POLICY_FIFO) {
> > struct drm_sched_job *next;
> > next = to_drm_sched_job(spsc_queue_peek(&entity->job_queue));
> > @@ -473,6 +503,8 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
> > struct drm_gpu_scheduler *sched;
> > struct drm_sched_rq *rq;
> > + WARN_ON(!!entity->single_sched);
> > +
> > /* single possible engine and already selected */
> > if (!entity->sched_list)
> > return;
> > @@ -522,16 +554,21 @@ void drm_sched_entity_select_rq(struct drm_sched_entity *entity)
> > void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
> > {
> > struct drm_sched_entity *entity = sched_job->entity;
> > + bool single_entity = !!entity->single_sched;
> > bool first;
> > trace_drm_sched_job(sched_job, entity);
> > - atomic_inc(entity->rq->sched->score);
> > + if (!single_entity)
> > + atomic_inc(entity->rq->sched->score);
> > WRITE_ONCE(entity->last_user, current->group_leader);
> > first = spsc_queue_push(&entity->job_queue, &sched_job->queue_node);
> > sched_job->submit_ts = ktime_get();
> > /* first job wakes up scheduler */
> > if (first) {
> > + struct drm_gpu_scheduler *sched =
> > + drm_sched_entity_to_scheduler(entity);
> > +
> > /* Add the entity to the run queue */
> > spin_lock(&entity->rq_lock);
> > if (entity->stopped) {
> > @@ -541,13 +578,14 @@ void drm_sched_entity_push_job(struct drm_sched_job *sched_job)
> > return;
> > }
> > - drm_sched_rq_add_entity(entity->rq, entity);
> > + if (!single_entity)
> > + drm_sched_rq_add_entity(entity->rq, entity);
> > spin_unlock(&entity->rq_lock);
> > - if (entity->rq->sched->sched_policy == DRM_SCHED_POLICY_FIFO)
> > + if (sched->sched_policy == DRM_SCHED_POLICY_FIFO)
> > drm_sched_rq_update_fifo(entity, sched_job->submit_ts);
> > - drm_sched_wakeup(entity->rq->sched);
> > + drm_sched_wakeup(sched);
> > }
> > }
> > EXPORT_SYMBOL(drm_sched_entity_push_job);
> > diff --git a/drivers/gpu/drm/scheduler/sched_fence.c b/drivers/gpu/drm/scheduler/sched_fence.c
> > index 7fd869520ef2..1ba5056851dd 100644
> > --- a/drivers/gpu/drm/scheduler/sched_fence.c
> > +++ b/drivers/gpu/drm/scheduler/sched_fence.c
> > @@ -167,7 +167,7 @@ void drm_sched_fence_init(struct drm_sched_fence *fence,
> > {
> > unsigned seq;
> > - fence->sched = entity->rq->sched;
> > + fence->sched = drm_sched_entity_to_scheduler(entity);
> > seq = atomic_inc_return(&entity->fence_seq);
> > dma_fence_init(&fence->scheduled, &drm_sched_fence_ops_scheduled,
> > &fence->lock, entity->fence_context, seq);
> > diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> > index 6777a2db554f..870568d94f1f 100644
> > --- a/drivers/gpu/drm/scheduler/sched_main.c
> > +++ b/drivers/gpu/drm/scheduler/sched_main.c
> > @@ -32,7 +32,8 @@
> > * backend operations to the scheduler like submitting a job to hardware run queue,
> > * returning the dependencies of a job etc.
> > *
> > - * The organisation of the scheduler is the following:
> > + * The organisation of the scheduler is the following for scheduling policies
> > + * DRM_SCHED_POLICY_RR and DRM_SCHED_POLICY_FIFO:
> > *
> > * 1. Each hw run queue has one scheduler
> > * 2. Each scheduler has multiple run queues with different priorities
> > @@ -41,7 +42,22 @@
> > * 4. Entities themselves maintain a queue of jobs that will be scheduled on
> > * the hardware.
> > *
> > - * The jobs in a entity are always scheduled in the order that they were pushed.
> > + * The organisation of the scheduler is the following for scheduling policy
> > + * DRM_SCHED_POLICY_SINGLE_ENTITY:
> > + *
> > + * 1. One to one relationship between scheduler and entity
> > + * 2. No priorities implemented per scheduler (single job queue)
> > + * 3. No run queues in scheduler rather jobs are directly dequeued from entity
> > + * 4. The entity maintains a queue of jobs that will be scheduled on the
> > + * hardware
> > + *
> > + * The jobs in a entity are always scheduled in the order that they were pushed
> > + * regardless of scheduling policy.
> > + *
> > + * A policy of DRM_SCHED_POLICY_RR or DRM_SCHED_POLICY_FIFO is expected to used
> > + * when the KMD is scheduling directly on the hardware while a scheduling policy
> > + * of DRM_SCHED_POLICY_SINGLE_ENTITY is expected to be used when there is a
> > + * firmare scheduler.
> > */
> > #include <linux/wait.h>
> > @@ -92,6 +108,8 @@ static inline void drm_sched_rq_remove_fifo_locked(struct drm_sched_entity *enti
> > void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts)
> > {
> > + WARN_ON(!!entity->single_sched);
> > +
> > /*
> > * Both locks need to be grabbed, one to protect from entity->rq change
> > * for entity from within concurrent drm_sched_entity_select_rq and the
> > @@ -122,6 +140,8 @@ void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts)
> > static void drm_sched_rq_init(struct drm_gpu_scheduler *sched,
> > struct drm_sched_rq *rq)
> > {
> > + WARN_ON(sched->sched_policy == DRM_SCHED_POLICY_SINGLE_ENTITY);
> > +
> > spin_lock_init(&rq->lock);
> > INIT_LIST_HEAD(&rq->entities);
> > rq->rb_tree_root = RB_ROOT_CACHED;
> > @@ -140,6 +160,8 @@ static void drm_sched_rq_init(struct drm_gpu_scheduler *sched,
> > void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
> > struct drm_sched_entity *entity)
> > {
> > + WARN_ON(!!entity->single_sched);
> > +
> > if (!list_empty(&entity->list))
> > return;
> > @@ -162,6 +184,8 @@ void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
> > void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
> > struct drm_sched_entity *entity)
> > {
> > + WARN_ON(!!entity->single_sched);
> > +
> > if (list_empty(&entity->list))
> > return;
> > @@ -691,7 +715,7 @@ int drm_sched_job_init(struct drm_sched_job *job,
> > struct drm_sched_entity *entity,
> > void *owner)
> > {
> > - if (!entity->rq)
> > + if (!entity->rq && !entity->single_sched)
> > return -ENOENT;
> > job->entity = entity;
> > @@ -724,13 +748,16 @@ void drm_sched_job_arm(struct drm_sched_job *job)
> > {
> > struct drm_gpu_scheduler *sched;
> > struct drm_sched_entity *entity = job->entity;
> > + bool single_entity = !!entity->single_sched;
> > BUG_ON(!entity);
> > - drm_sched_entity_select_rq(entity);
> > - sched = entity->rq->sched;
> > + if (!single_entity)
> > + drm_sched_entity_select_rq(entity);
> > + sched = drm_sched_entity_to_scheduler(entity);
> > job->sched = sched;
> > - job->s_priority = entity->rq - sched->sched_rq;
> > + if (!single_entity)
> > + job->s_priority = entity->rq - sched->sched_rq;
> > job->id = atomic64_inc_return(&sched->job_id_count);
> > drm_sched_fence_init(job->s_fence, job->entity);
> > @@ -954,6 +981,13 @@ drm_sched_select_entity(struct drm_gpu_scheduler *sched)
> > if (!drm_sched_ready(sched))
> > return NULL;
> > + if (sched->single_entity) {
> > + if (drm_sched_entity_is_ready(sched->single_entity))
> > + return sched->single_entity;
> > +
> > + return NULL;
> > + }
> > +
> > /* Kernel run queue has higher priority than normal run queue*/
> > for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
> > entity = sched->sched_policy == DRM_SCHED_POLICY_FIFO ?
> > @@ -1210,6 +1244,7 @@ int drm_sched_init(struct drm_gpu_scheduler *sched,
> > return -EINVAL;
> > sched->ops = ops;
> > + sched->single_entity = NULL;
> > sched->hw_submission_limit = hw_submission;
> > sched->name = name;
> > sched->run_wq = run_wq ? : system_wq;
> > @@ -1222,7 +1257,9 @@ int drm_sched_init(struct drm_gpu_scheduler *sched,
> > sched->sched_policy = default_drm_sched_policy;
> > else
> > sched->sched_policy = sched_policy;
> > - for (i = DRM_SCHED_PRIORITY_MIN; i < DRM_SCHED_PRIORITY_COUNT; i++)
> > + for (i = DRM_SCHED_PRIORITY_MIN; sched_policy !=
> > + DRM_SCHED_POLICY_SINGLE_ENTITY && i < DRM_SCHED_PRIORITY_COUNT;
> > + i++)
> > drm_sched_rq_init(sched, &sched->sched_rq[i]);
> > init_waitqueue_head(&sched->job_scheduled);
> > @@ -1255,7 +1292,15 @@ void drm_sched_fini(struct drm_gpu_scheduler *sched)
> > drm_sched_run_wq_stop(sched);
> > - for (i = DRM_SCHED_PRIORITY_COUNT - 1; i >= DRM_SCHED_PRIORITY_MIN; i--) {
> > + if (sched->single_entity) {
> > + spin_lock(&sched->single_entity->rq_lock);
> > + sched->single_entity->stopped = true;
> > + spin_unlock(&sched->single_entity->rq_lock);
> > + }
> > +
> > + for (i = DRM_SCHED_PRIORITY_COUNT - 1; sched->sched_policy !=
> > + DRM_SCHED_POLICY_SINGLE_ENTITY && i >= DRM_SCHED_PRIORITY_MIN;
> > + i--) {
> > struct drm_sched_rq *rq = &sched->sched_rq[i];
> > if (!rq)
> > @@ -1299,6 +1344,8 @@ void drm_sched_increase_karma(struct drm_sched_job *bad)
> > struct drm_sched_entity *entity;
> > struct drm_gpu_scheduler *sched = bad->sched;
> > + WARN_ON(sched->sched_policy == DRM_SCHED_POLICY_SINGLE_ENTITY);
> > +
> > /* don't change @bad's karma if it's from KERNEL RQ,
> > * because sometimes GPU hang would cause kernel jobs (like VM updating jobs)
> > * corrupt but keep in mind that kernel jobs always considered good.
> > diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
> > index 3df801401028..669d6520cd3a 100644
> > --- a/include/drm/gpu_scheduler.h
> > +++ b/include/drm/gpu_scheduler.h
> > @@ -70,6 +70,7 @@ enum drm_sched_policy {
> > DRM_SCHED_POLICY_DEFAULT,
> > DRM_SCHED_POLICY_RR,
> > DRM_SCHED_POLICY_FIFO,
> > + DRM_SCHED_POLICY_SINGLE_ENTITY,
> > DRM_SCHED_POLICY_COUNT,
> > };
> > @@ -103,6 +104,9 @@ struct drm_sched_entity {
> > */
> > struct drm_sched_rq *rq;
> > + /** @single_sched: Single scheduler */
> > + struct drm_gpu_scheduler *single_sched;
> > +
> > /**
> > * @sched_list:
> > *
> > @@ -488,6 +492,7 @@ struct drm_sched_backend_ops {
> > * struct drm_gpu_scheduler - scheduler instance-specific data
> > *
> > * @ops: backend operations provided by the driver.
> > + * @single_entity: Single entity for the scheduler
> > * @hw_submission_limit: the max size of the hardware queue.
> > * @timeout: the time after which a job is removed from the scheduler.
> > * @name: name of the ring for which this scheduler is being used.
> > @@ -519,6 +524,7 @@ struct drm_sched_backend_ops {
> > */
> > struct drm_gpu_scheduler {
> > const struct drm_sched_backend_ops *ops;
> > + struct drm_sched_entity *single_entity;
> > uint32_t hw_submission_limit;
> > long timeout;
> > const char *name;
> > @@ -604,6 +610,8 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
> > struct drm_gpu_scheduler **sched_list,
> > unsigned int num_sched_list,
> > atomic_t *guilty);
> > +struct drm_gpu_scheduler *
> > +drm_sched_entity_to_scheduler(struct drm_sched_entity *entity);
> > long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout);
> > void drm_sched_entity_fini(struct drm_sched_entity *entity);
> > void drm_sched_entity_destroy(struct drm_sched_entity *entity);
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